Bearing lubricating device

ABSTRACT

A bearing lubricating device .[.which.]. is designed for attachment to the wheel bearing housing of a trailer or other vehicle to automatically lubricate the bearings in the bearing housing. The bearing lubricating device includes a cylindrical grease housing fitted with a spring-loaded piston and a piston plate extending from the piston, wherein the piston projects from the end of the grease housing. When grease is charged into the interior of the grease housing, the spring is compressed and forces the piston farther outwardly of the grease housing, to indicate that sufficient grease is provided in the grease housing for proper lubrication of the wheel bearings. In a first preferred embodiment of the invention a stop ring is provided in the housing to limit travel of the piston plate and piston in the housing and the projecting end of the piston is color-coded to indicate the grease content inside the grease housing. In a second preferred embodiment a retainer is attached to the piston for the same purpose.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to the lubrication of wheel bearings in trailersand other vehicles and more particularly, to a bearing lubricatingdevice which is designed to self-lubricate trailer wheel bearings byoperation of a spring-loaded piston located in a cylindrical housingcontaining a supply of lubricant, such as grease. The bearinglubricating device is characterized by a cylindrically-shaped greasehousing, one end of which is open and adapted to fit in the wheelbearing housing of the wheel of a trailer or other vehicle, the open endcommunicating with a grease chamber located adjacent to the outsidewheel bearing. A spring-loaded piston and piston plate combination islocated in the grease housing, with the piston plate contacting thesupply of grease, in order to bias the grease into contact with thewheel bearings and continually lubricate the wheel bearings as thetrailer or other vehicle is operated and the wheels rotate. The free endof the piston projects through an opening in the end of the greasehousing and in a first preferred embodiment of the invention, a stopring is mounted in the housing to arrest the travel of the piston plateand piston and the projecting end of the piston is color-coded toindicate when the supply of grease in the grease housing is sufficientto properly lubricate both the inside and outside wheel bearings. In asecond preferred embodiment a piston retainer is fitted over theprojecting end of the piston and serves both to limit the travel of thepiston inwardly of the bearing lubricating device and to indicate whenthe supply of grease in the grease housing has reached a sufficientlylow level to require recharging of the grease housing. In anotherpreferred embodiment of the invention, a grease fitting is seated in theside of the cylindrical grease housing, for charging the grease housingwith grease and in a still further preferred embodiment of theinvention, the grease fitting is located in the projecting end of thepiston and grease is charged into the grease housing through alongitudinal grease supply passage or bore provided in the piston andcommunicating with the grease housing.

One of the problems which has long existed in the towing of varioustypes of trailers and similar vehicles is that of failure of the wheelbearings in these trailers and vehicles. Trailers such as boat trailers,utility trailers, cattle trailers and the like, all utilize wheelbearings which must be periodically packed with grease and ultimatelyreplaced, sometimes frequently under circumstances where these trailersare towed long distances. Furthermore, boat trailers are periodicallysubmerged when boats are launched in lakes and other waterways.Accordingly, the water washes the grease from within the wheel bearinghousings, thereby causing the wheel bearings to be improperly lubricatedand sometimes ruined, due to the development of friction and excessiveheat while the trailer is towed. This circumstance necessitates alengthy and sometimes expensive repair operation to replace one .[.o.]..Iadd.or .Iaddend.both of the inside and outside wheel bearings in eachwheel. The bearings must therefore be frequently lubricated, atime-consuming task which requires that the trailer be jacked to freethe wheel, the bearing hub and wheel removed and the inside and outsidebearings then removed from the bearing housing in the wheel, washed freeof old grease, repacked with new grease and replaced in the bearinghousing.

2. Description of the Prior Art

Various devices for lubricating wheel bearings and other bearings, aswell as warning an operator as to the insufficiency of lubrication ofthese bearings, are known in the art. L. H. Des Isles U.S. Pat. No.859,925, dated Jul. 16, 1907, details an "Alarm Signal for MovableBearings". The device detailed in this patent provides a bell or alarmsounder conveniently mounted directly upon the crank pin, crosshead andlike shifting bearings in a machine and so arranged that the bell oralarm sounder will be actuated by the movement of the bearings when thelatter become overheated. An "Oiling Device" is detailed in M. E.Brigham U.S. Pat. No. 915,731, dated Mar. 23, 1909. The device includesan oil chamber having multiple outlets from which oil is supplied todifferent parts of a machine to be lubricated, along with means forsupplying the chamber with oil under pressure and control devices forregulating the automatic flow of oil through the outlets in a selectedtime period, J. T. Leonard U.S. Pat. No. 2,526,568, dated Oct. 17, 1950,details a "Lubricating Apparatus", which includes a measuring valve thatis durable and reliable in operation and may be economicallymanufactured and adapted for use in a machine, either with grease orwith oil as the lubricant. .Iadd.M. J. Alger, Jr. .Iaddend.U.S. Pat. No.2,694,997, dated Nov. 23, 1954, describes a signal device for indicatingoverheated bearings. The signal device is particularly useful as anindication that the journal bearing of a railroad car has becomeoverheated and is adapted for permanent attachment on the journal axleof the railroad car to accomplish this objective. A "Method andApparatus for Observing, Indicating and Maintaining Fluid Level" isdetailed in Michael R. Swearingen U.S. Pat. No. 3,983,958, dated Oct. 5,1976. The apparatus is designed for attachment to a bearing housingthrough an access conduit which provides for observation of thelubricating oil in the bearing housing, thereby ascertaining the levelof the oil in the lubricating housing and maintaining a desired fluidlevel in the bearing. A "Lubricating Device" is detailed in T. G.Kincaid U.S. Pat. No. 960,341, dated Jun. 7, 1910. The Kincaid device ischaracterized by a grease reservoir adapted to contain a stick ofsemi-solid lubricant. The reservoir includes a conical bottom whichforms an auxiliary grease chamber and panels are provided in the bottomof the reservoir from the lower outer edge of the bottom into theauxiliary chamber at the apex of the cone. A cap is adjustable securedto the reservoir and includes an opening at the top and a spring-pressplunger is disposed within the reservoir, with a graduated stemprojecting through the opening of the cap and adapted to indicate thequantity of grease contained in the reservoir.

Various types of self-lubricating devices, one of which is marketedunder the trademark "Bearing Buddy", are currently used to lubricate thewheel bearings in trailers and similar vehicles. These devices arepatterned after the T. G. Kincaid lubricating device and each includes agrease chamber disposed within a cylindrical housing, a spring-loadedplate slidably mounted in the housing and a grease fitting provided inthe housing for charging the housing with grease and forcing thespring-loaded plate outwardly. The spring-loaded plate continuallyexerts pressure against the grease and causes the grease to enter thewheel bearing housing and coat the wheel bearings.

Problems which are characteristic of these self-lubricating devices.[.is the combination of.]. .Iadd.are .Iaddend.complexity, the lack offacility for quickly determining when the grease housing needsrecharging and the difficulty in recharging the grease housing quicklyand efficiently, without overcharging. Accordingly, it is an object ofthis invention to provide a new and improved bearing lubricating devicewhich is capable of self-lubricating the wheel bearings of a trailer orother vehicle by mounting in the vehicle bearing housing, automaticallyforcing grease from the interior of the bearing lubricating device intothe bearing housing to coat the bearings therein and externallyindicating when the grease supply in the bearing lubricating device islow.

Another object of the invention is to provide a bearing lubricatingdevice which is capable of being removably mounted in the wheel bearingof a trailer or similar vehicle for self-lubricating the wheel bearingstherein and indicating the relative quantity of grease located in thedevice, which bearing lubricating device is characterized by a pistonhaving a color-coded end projecting through the end of thegrease-containing housing to indicate the quantity of grease provided inthe housing.

A still further object of the invention is to provide a bearinglubricating device for lubricating the wheel bearings in trailers andother vehicles, which device includes a cylindrical,lubricant-containing housing provided with a spring-loaded piston whichprojects through an opening in the housing, which housing receives aretainer to prevent the piston from recessing in the housing, andfurther including a grease fitting located in the housing forperiodically recharging the housing with lubricant.

Still another object of the invention is to provide a bearinglubricating device which is designed to self-lubricate the wheelbearings of a boat trailer or other vehicle, which bearing lubricatingdevice is characterized by a cylindrical, grease-containing housingprovided with spaced air and grease weep holes, respectively, aspring-loaded piston plate and piston slidably disposed in the housingand a grease fitting located in the end of the piston which projectsthrough the end of the grease-containing housing, for periodicallycharging grease into the housing.

Yet another object of the invention is to provide a new and improvedbearing lubricating device for lubricating the inside and outside wheelbearings of a trailer or other vehicle, which device includes acylindrical housing, one end of which is open and adapted for removableinsertion in the bearing housing of the trailer and further including apair of spaced weep and air expulsion holes, respectively, and a closedend located opposite the open end. A piston extends through an openingprovided in the closed end of the grease housing and a round,spring-loaded piston plate is provided on the opposite end of the pistonfor traversing a segment of the inside chamber of the housing andforcing grease into the bearing housing.

SUMMARY OF THE INVENTION

These and other objects of the invention are provided in a new andimproved bearing lubricating device which includes a cylindrical,grease-containing housing having a closed end and the opposite end openand adapted for removable insertion in the bearing housing of a traileror other vehicle, a spring-loaded piston and piston plate slidablydisposed in the housing, for biasing the grease into the bearing housingand .[.i.]. .Iadd.in .Iaddend.contact with the inside and outsidetrailer bearings, wherein the piston extends through the front of thegrease housing for indicating the quantity of grease in the greasehousing. In a preferred embodiment of the invention a stop ring isseated in the housing for limiting the travel of the piston plate andpiston and the extending end of the piston is color-coded to indicatethe quantity of grease in the grease chamber and in another preferredembodiment, a retainer is provided on the extending end of the piston toprevent the piston from recessing in the grease housing as the grease isdepleted. The bearing lubricating device is provided with a greasefitting which is optionally located in the housing or in the end of thepiston, for periodically introducing grease into the grease housing.

BRIEF DESCRIPTION OF THE DRAWING

The invention will be better understood by reference to the accompanyingdrawing, wherein:

FIG. 1 is a perspective view of a first preferred embodiment of thebearing lubricating device of this invention, with the piston inrecessed configuration, indicating that grease in the grease chamber isdangerously depleted;

FIG. 2 is a sectional view taken along line 2--2 of the bearinglubricating device illustrated in FIG. 1;

FIG. 3 is a perspective view of the bearing lubricating deviceillustrated in FIG. 1, with the piston in extended configuration,indicating that grease in the grease chamber is at full capacity;

FIG. 4 is a sectional view taken along line 4--4 of the bearinglubricating device illustrated in FIG. 3;

FIG. 5 is a sectional view of a second preferred embodiment of thebearing lubrication of this invention, wherein the grease fitting islocated in the extending end of the piston;

FIG. 6 is a sectional view of yet another preferred embodiment of thebearing lubricating device, wherein a piston stop ring is provided inthe grease housing, in order to limit the inward travel of the piston;and

FIG. 7 is a side view of the piston illustrated in FIG. 6, with apreferred color-coding provided thereon to indicate when the greasechamber needs to be recharged with grease.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring initially to FIGS. 1-4 of the drawing, in a first preferredembodiment the bearing lubricating device of this invention is generallyindicated by reference numeral 1. The bearing lubricating device 1includes a grease housing 2 having a cylindrical housing side 3, whichis closed at one end by a housing end 4 and is open at the opposite end.A shoulder 5 is provided in the opposite end of the grease housing 2 andthe opposite end is terminated by hub-engaging segment 6, which isdesigned to seat in the bearing housing opening 38 of a bearing housing37 in a trailer (not illustrated), as illustrated in FIGS. 2 and 4. Aportion of an outside wheel bearing 39 is illustrated in functionalconfiguration in the bearing housing 37 and an inside wheel bearing (notillustrated) is mounted in the bearing housing 37 in spaced relationshipwith respect to the outside wheel bearing 39. As further illustrated inFIGS. 2 and 4, a piston access opening 7 is provided in the flat housingend 4 of the grease housing 2 and an air escape duct 8 is drilled orotherwise provided in the housing side 3, immediately adjacent to thehousing end 4. A grease weep duct 9 is similarly drilled or otherwiseprovided in the housing side 3 in spaced relationship with respect tothe air escape duct 8 and the air escape duct 8 communicates with aspring chamber 33, located in the forward end of the grease housing 2,while the grease weep duct 9 communicates with the grease chamber 27,located in the rear end of the grease housing 2, when the grease chamber27 is charged with grease, as illustrated in FIG. 4. A piston O-ringgroove 10 is provided inside the housing end 4 in communication with thepiston access opening 7 and a piston O-ring 11 is seated in the pistonO-ring groove 10, for purposes which will be hereinafter furtherdescribed. A grease fitting seat 12 is also provided in the housing side3 of the grease housing 2 and includes seat threads 13, for receivingthe grease fitting threads 29 of a grease fitting 28, having a greasefitting nozzle 30 for receiving the charging end of a grease gun (notillustrated) and charging grease into the grease chamber 27, ashereinafter described. In a preferred embodiment of the invention anozzle cap retainer 32 .[.i.]. .Iadd.is .Iaddend.designed to removablyfit over the grease fitting nozzle 30 and is retained on the greasefitting 28 by means of a nozzle cap retainer 32, in order to preventdust or other foreign material from plugging the opening in the greasefitting nozzle 30 when the grease fitting 28 is not in use.

As further illustrated in FIGS. 1-4, a piston 15 is slidably disposedand sealed by means of the piston O-ring 11 in the piston access opening7, with the piston end 16 of the piston 15 extending from the housingend 4 and the opposite end joining or formed integrally with pistonplate 21. The piston plate 21 is round and includes a plate O-ringgroove 22 at the periphery thereof, which receives a plate O-ring 23 forsealing the space between the periphery of the piston plate 21 and theinner wall of the grease housing 2. A piston plate spring 24 is disposedin the spring chamber 33 between the piston plate 21 and the housing end4, as illustrated in FIG. 2. In a preferred embodiment of the inventiona piston retainer 17 is tightly seated on the piston 15 and includes aflared cap flange 19. As illustrated in FIGS. 1 and 3, flange tabs 20are provided in the cap flange 19, in order to tightly secure the capflange 19 of the piston cap 17 on the piston 15, spaced from the pistonend 16.

Referring now to FIG. 5 of the drawing, in another preferred embodimentof the invention, the bearing lubricating device 1 is characterized by agrease fitting 28 which is threadably mounted in the piston end 16 ofthe piston 15 by means of the grease fitting threads 29. A grease supplypassage 14 is drilled or otherwise longitudinally provided in the piston15 and communicates with a grease supply opening (not illustrated)provided in the grease fitting 28, in order to introduce a supply ofgrease through the grease fitting nozzle 30 of the grease fitting 28,into the piston bore 14 and finally into the grease chamber 27. In thebearing lubricating device illustrated in FIG. 5, the displacement ofthe piston plate spring 24 is chosen such that when the piston platespring 24 is open in non-biasing configuration in the spring chamber 33as illustrated, the piston plate spring 24 exerts no rearward pressureagainst the piston-plate 21 and the grease located in the grease chamber27. Furthermore, the retainer flange 19 of the piston retainer 17contacts the housing end 4 and prevents the piston plate 21 from movingfurther toward the wheel bearing 39 and the piston 15 and grease fitting28 from depressing inside the piston .[.bore.]. .Iadd.access opening.Iaddend.7 of the grease housing 2.

Referring now to FIGS. 6 and 7 of the drawings, under circumstanceswhere it is desired to insure that the extending piston end 16 of thepiston 15 does not recess inside the grease housing 2 undercircumstances where no piston retainer 17 is inserted on the piston 15,a piston stop ring 25 is seated in a stop ring groove 26 located in theinterior wall of the grease housing 2. The piston stop ring 25 serve toblock the path of the piston plate 21 against the bias of the pistonplate spring 24, located in the spring chamber 33, regardless of thedepletion of grease in the grease chamber 27. Accordingly, in thisembodiment of the invention there is no necessity for mounting a pistonretainer 17 on the piston 15, since this extending end is always exposedregardless of the quantity of grease located in the grease chamber 27.As illustrated in FIG. 7, the extending end of the piston 15 can beprovided with a red-color area 34, located adjacent to the piston end 16and a green-color area 35 located immediately adjacent to the red-colorarea 34, in order to facilitate determining at a glance the quantity ofgrease in the grease chamber 27, as hereinafter further described.

Referring again to FIGS. 1-4 of the drawing, when the grease chamber 27in the grease housing 2 of the bearing lubricating device 1 is empty, orif there is insufficient grease therein to compress the piston platespring 24, the piston plate spring 24 is extended inwardly of the greasehousing 2 in non-biased configuration, as illustrated in FIG. 2.Introduction of grease into the grease chamber 27 through the greasefitting 28 by means of a grease gun (not illustrated), exerts pressureagainst the piston plate 21 and compresses the piston plate spring 24,as air is forced from the spring chamber 33 through the air escape duct8. When the piston plate spring 24 is fully compressed as illustrated inFIG. 4, grease is caused to escape from the grease chamber 27 of thegrease housing 2 through the grease weep duct 9, thereby notifying theoperator that the grease chamber 27 is full. The grease gun is thenremoved from attachment to the grease fitting nozzle 30 and the nozzlecap 31 is snapped over the grease fitting nozzle 30, as illustrated inFIG. 4. Pressure is now constantly applied to the piston plate 21 andthe grease located in the grease chamber 27 by the bias in the pistonplate spring 24, to force grease into the bearing housing opening 38 ofthe bearing housing 37 and coat the outside wheel bearing 39 as well asthe corresponding inside wheel bearing (not illustrated). When thebearing lubricating device 1 is in the loaded configuration illustratedin FIGS. 3 and 4 the piston end 16 of the piston 15 is extended from thehousing end 4 along with the piston retainer 17, which provides a visualindication of the quantity of grease located in the grease chamber 27.As the grease in the grease chamber 27 is alternately heated and cooleddue to repeated wheel rotation, it is forced farther into the bearinghousing 37 and both the piston 15 and the piston plate 21 slowlyapproach the wheel bearing 39 responsive to the bias of the piston platespring 24. This process continues until the piston retainer 17 contactsthe housing end 4 of the grease housing 2, as illustrated in FIGS. 1 and2 of the drawing. Under these circumstances, additional grease must becharged into the grease chamber 27, in order to prevent excessive wearand ultimate failure of the outside wheel bearing 39, as well as thecompanion inside wheel bearing (not illustrated).

Referring again to the drawing, whether or not a piston retainer 17 isused on the piston 15 to control recessing of the piston 15 in thehousing end 4, the extending end of the piston 15 may be color-codedwith the red-color area 34 and the green-color area 35 as illustrated inFIG. 7, to visually indicate the quantity of grease provided in thegrease chamber 27. For example, as illustrated in FIG. 6, undercircumstances where the piston plate 21 is depressed toward the wheelbearing 39 to a maximum extent and lies against the piston stop ring 25,the piston 15 is retracted inside the housing end 4 such that only thered-color area 34 is visible to an observer. This indicates that thegrease chamber 27 is depleted and additional grease should be chargedinto the grease chamber 27, in order to extend the piston 15 furtheroutwardly of the housing end 4 such that the green-color area 35 isvisible. As heretofore described, charging of the grease chamber 27 iseffected by attaching a grease gun (not illustrated) to the greasefitting nozzle 30 of a grease fitting 28, which is either mounted in thehousing side 3 of the grease housing 2 as illustrated in FIG. 6, or inthe piston end 16 of the piston 15, as illustrated in FIG. 5.

It will be appreciated by those skilled in the art that the bearinglubricating device of this invention facilitates a quick, efficient andprotective technique for providing grease to the wheel bearings oftrailers and other vehicles. In each of the several embodiments of thebearing lubricating device, the observer can tell at a glance whether ornot the wheel bearings are receiving a proper amount of grease and cantake the required steps. In a most preferred embodiment of the inventionthe grease housing 2 is constructed to anodized aluminum to preventcorrosion and distortion from repeated fillings with grease, as well asto minimize damage from rocks and other objects struck by the towingvehicle and trailer wheels. Moreover, any lubricant such as grease,having a viscosity and composition suitable for lubricating wheelbearings can be used in the bearing lubricating device, according to theknowledge of those skilled in the art.

While the preferred embodiments of the invention have been describedabove, it will be recognized and understood that various modificationsmay be made therein and the appended claims are intended to cover allsuch modifications which may fall within the spirit and scope of theinvention.

Having described my invention with the particularity set forth above,what is claimed is:
 1. A bearing lubricating device for lubricatingwheel bearings, comprising a generally cylindrically-shaped housingadapted to contain a lubricant, said housing having a closed end and anopen end provided in communication with the wheel bearings; piston meansslidably disposed in said housing, with one end of said piston meansslidably projecting from said closed end of said housing; bias meansprovided in said housing, said bias means engaging said piston means forbiasing said piston means inwardly of said housing and forcing thelubricant into contact with the wheel bearings; and a lubricant fittingseated in said housing for selectively introducing fresh lubricant intosaid housing.
 2. The bearing lubricating device of claim 1 furthercomprising an air escape duct provided in said housing for allowing airto escape from said housing when the lubricant is introduced into saidhousing through said lubricant fitting.
 3. The bearing lubricatingdevice of claim 1 further comprising a lubricant weep duct provided insaid housing for indicating when said housing is substantially filledwith the lubricant.
 4. The bearing lubricating device of claim 1 furthercomprising:(a) an air escape duct provided in said housing for allowingair to escape from said housing when the lubricant is introduced intosaid housing through said lubricant fitting; and (b) a lubricant weepduct provided in said housing for indicating when said housing issubstantially filled with the lubricant.
 5. The bearing lubricant deviceof claim 1 further comprising a lubricant supply passage provided insaid piston means and wherein said lubricant fitting is relocated insaid piston means in communication with said lubricant supply passage.6. The bearing lubricating device of claim 1 further comprising:(a) anair escape duct provided in said housing for allowing air to escape fromsaid housing when the lubricant is introduced into said housing throughsaid lubricant fitting; (b) a lubricant weep duct provided in saidhousing for indicating when said housing is substantially filled withthe lubricant; and (c) a lubricant supply passage provided in saidpiston means and wherein said lubricant fitting is relocated in saidpiston means in communication with said grease supply passage.
 7. Thebearing lubricating device of claim 1 wherein said piston means furthercomprises a round piston plate slidably disposed in said housing betweensaid closed end and said open end of said housing, and an elongatedpiston extending from said piston plate and having a piston end slidablyextending through said closed end of said housing, and furthercomprising:(a) piston seal means provided in said closed end of saidhousing for sealing said piston in slidable relationship in said closedend of said housing; and (b) piston plate seal means provided in theperiphery of said piston plate for sealing said piston plate in slidablerelationship in said housing.
 8. The bearing lubricating device of claim7 further comprising an air escape duct provided in said housing forallowing air to escape from said housing when the lubricant isintroduced into said housing through said lubricant fitting.
 9. Thebearing lubricating device of claim 8 further comprising a lubricantweep duct provided in said housing for indicating when said housing issubstantially filled with the lubricant.
 10. The bearing lubricatingdevice of claim 9 further comprising a lubricant supply passagelongitudinally provided in said piston and said piston plate, saidlubricant supply passage communicating with the lubricant in saidhousing, and wherein said lubricant fitting is relocated in said pistonin communication with said lubricant supply passage.
 11. The bearinglubricating device of claim 7 wherein said bias means further comprisesa coil spring disposed in said housing between said piston plate andsaid closed end of said housing.
 12. The bearing lubricating device ofclaim 11 further comprising:(a) an air escape duct provided in saidhousing for allowing air to escape from said housing when the lubricantis introduced into said housing through said lubricant fitting; and (b)a lubricant weep duct provided in said housing for indicating when saidhousing is substantially filled with the lubricant.
 13. The bearinglubricating device of claim 7 further comprising first and second colorindicia provided on said piston end of said piston, for approximatelyindicating the quantity of lubricant in said housing responsive toslidable movement of said piston and said piston plate in said housing.14. The bearing lubricating device of claim 13 further comprising:(a) anair escape duct provided in said housing for allowing air to escape fromsaid housing when the lubricant is introduced into said housing throughsaid lubricant fitting; and (b) a lubricant weep duct provided in saidhousing for indicating when said housing is substantially filled withthe lubricant.
 15. The bearing lubricating device of claim 14 furthercomprising a lubricant supply passage longitudinally provided in saidpiston and said piston plate, said lubricant supply passagecommunicating with the lubricant in said housing and wherein saidlubricant fitting is relocated in said piston in communication with saidlubricant supply passage.
 16. The bearing lubricating device of claim 15wherein said bias means further comprises a coil spring disposed in saidhousing between said piston plate and said closed end of said housing.17. The bearing lubricating device of claim 7 further comprising a stopring groove provided in the inside wall of said housing in spacedrelationship with respect to said closed end of said housing and a stopring seated in said stop ring groove, for arresting the travel of saidpiston plate inwardly of said housing, responsive to the bias in saidbias means.
 18. The bearing lubricating device of claim 17 furthercomprising:(a) an air escape duct provided in said housing for allowingair to escape from said housing when the lubricant is introduced intosaid housing through said lubricant fitting; and (b) a lubricant weepduct provided in said housing for lubricating when said housing issubstantially filled with the lubricant.
 19. The bearing lubricatingdevice of claim 17 further comprising first and second color indiciaprovided on said piston end of said piston, for approximately indicatingthe quantity of lubricant in said housing, responsive to slidablemovement of said piston and said piston plate in said housing.
 20. Thebearing lubricating device of claim 17 further comprising:(a) an airescape duct provided in said housing for allowing air to escape fromsaid housing when the lubricant is introduced into said housing throughsaid lubricant fitting; (b) a lubricant weep duct provided in saidhousing for indicating when said housing is substantially filled withthe lubricant; and (c) first and second color indicia provided on saidpiston end of said piston, for approximately indicating the quantity oflubricant in said housing, responsive to slidable movement of saidpiston and said piston plate in said housing.
 21. The bearinglubricating device of claim 17 further comprising a lubricant supplypassage longitudinally provided in said piston and said piston plate,said lubricant supply passage communicating with the lubricant in saidhousing, and wherein said lubricant fitting is relocated in said pistonin communication with said lubricant supply passage.
 22. The bearinglubricating device of claim 17 wherein said bias means further comprisesa coil spring disposed in said housing between said piston plate andsaid closed end of said housing and further comprising:(a) an air escapeduct provided in said housing for allowing air to escape from saidhousing when the lubricant is introduced into said housing through saidlubricant fitting; (b) a lubricant weep duct provided in said housingfor indicating when said housing is substantially filled with thelubricant; (c) first and second color indicia provided on said pistonend of said piston, for approximately indicating the quantity oflubricant in said housing; and (d) a lubricant supply passagelongitudinally provided in said piston and said piston plate, saidlubricant supply passage communicating with the lubricant in saidhousing, and wherein said lubricant fitting is relocated in said pistonin communication with said lubricant supply passage.
 23. The bearinglubricating device of claim 7 further comprising retainer means disposedon said piston end, whereby said piston end is prevented from recessingin said opposite end of said housing responsive to the bias of said biasmeans when the quantity of lubricant is reduced in said housing.
 24. Thebearing lubricating device of claim 23 further comprising an air escapeduct provided in said housing for allowing air to escape from saidhousing when the lubricant is introduced into said housing through saidlubricant fitting.
 25. The bearing lubricating device of claim 23further comprising a lubricant weep duct provided in said housing forindicating when said housing is substantially filled with the lubricant.26. The bearing lubricating device of claim 23 wherein said bias meansfurther comprises a coil spring disposed in said housing between saidpiston plate and said opposite end of said housing.
 27. The bearinglubricating device of claim 23 wherein said bias means further comprisesa coil spring disposed in said housing between said piston plate andsaid opposite end of said housing and further comprising:(a) an airescape duct provided in said housing for allowing air to escape fromsaid housing when the lubricant is introduced into said housing throughsaid lubricant fitting; and (b) a lubricant weep duct provided in saidhousing for indicating when said housing is substantially filled withthe lubricant.
 28. The bearing lubricating device of claim 27 whereinsaid retainer means further comprises a flange and a plurality of flangetabs provided in said flange for engaging said piston, said flangeadapted to engage said opposite end of said housing and arrest thetravel of said piston plate inwardly of said housing responsive to thebias in said coil spring.
 29. The bearing lubricating device of claim 28further comprising first color indicia provided on said flange and saidpiston end of said piston and second color indicia provided on saidpiston adjacent to said first color indicia, for approximatelyindicating the quantity of lubricant in said housing, responsive toslidable movement of said piston and said piston plate in said housing.30. A bearing lubricating device for mounting in a wheel housing andlubricating wheel bearings provided in the wheel housing, said bearinglubricating device comprising a generally cylindrically-shaped housingadapted to contain a lubricant and having a closed end and an open endspaced from said closed end, said open end provided in communicationwith the wheel bearings; a stop ring groove provided in the inside wallof said housing in spaced relationship with respect to said closed endof said housing and a stop ring seated in said stop ring groove; a roundpiston plate slidably disposed in said housing between said stop ringand said closed end of said housing and piston plate seal means providedin the periphery of said piston plate for sealing said piston plate inslidable relationship in said housing; a piston access opening providedin said closed end of said housing and piston seal means provided insaid piston access opening; a piston extending from said piston platethrough said piston access opening and said seal means, wherein saidpiston is sealed in slidable relationship in said piston access openingby said piston seal means; a coil spring located in said housing betweensaid piston plate and said closed end of said housing for biasing saidpiston plate toward said open end of said housing; and a lubricantfitting seated in said housing for selectively introducing freshlubricant into said housing, whereby said piston plate exerts pressureon lubricant provided in said housing between said piston plate and saidopen and .[.and.]. causes the lubricant to coat the wheel bearings,responsive to the bias of said coil spring.
 31. The bearing lubricatingdevice of claim 30 further comprising an air escape duct provided insaid housing for allowing air to escape from said housing when thelubricant is introduced into said housing through said lubricantfitting.
 32. The bearing lubricating device of claim 30 furthercomprising a lubricant weep duct provided in said housing for indicatingwhen said housing is substantially filled with the lubricant.
 33. Thebearing lubricating device of claim 30 further comprising a lubricantsupply passage provided in said piston and said piston plate, saidlubricant supply passage communicating with the lubricant in saidhousing, and wherein said lubricant fitting is relocated in theextending end of said piston, said lubricant fitting provided incommunication with said lubricant supply passage, for selectivelyintroducing lubricant into said housing.
 34. The bearing lubricatingdevice of claim 30 further comprising:(a) an air escape duct provided insaid housing for allowing air to escape from said housing when thelubricant is introduced into said housing through said lubricantfitting; and (b) a lubricant weep duct provided in said housing forindicating when said housing is substantially filled with the lubricant.35. The bearing lubricating device of claim 34 further comprising alubricant supply passage provided in said piston and said piston plate,said lubricant supply passage communicating with the lubricant in saidhousing, and wherein said lubricant fitting is relocated in theextending end of said piston, said lubricant fitting provided incommunication with said lubricant supply passage, for selectivelyintroducing lubricant into said housing.
 36. The bearing lubricatingdevice of claim 30 further comprising first and second color indiciaprovided on the extending end of said piston, for approximatelyindicating the quantity of lubricant in said housing, responsive toslidable movement of said piston and said piston plate in said housing.37. The bearing lubricating device of claim 30 further comprising:(a) anair escape duct provided in said housing for allowing air to escape fromsaid housing when the lubricant is introduced into said housing throughsaid lubricant fitting; (b) a lubricant weep duct provided in saidhousing for indicating when said housing is substantially filled withthe lubricant; and (c) first and second color indicia provided on theextending end of said piston, for approximately indicating the quantityof lubricant in said housing, responsive to slidable movement of saidpiston and said piston plate in said housing.
 38. The bearinglubricating device of claim 37 further comprising a lubricant supplypassage provided in said piston and said piston plate, said lubricantsupply passage communicating with the lubricant in said housing, andwherein said lubricant fitting is relocated in the extending end of saidpiston in communication with said lubricant supply passage.
 39. Abearing lubricating device for mounting in a wheel housing andlubricating wheel bearings provided in the wheel housing, said bearinglubricating device comprising a generally cylindrically-shaped housingadapted to contain a lubricant and having a closed end and an open endspaced from said closed end, said open end provided in communicationwith the wheel bearings; a round piston plate slidably disposed in saidhousing between said open end and said closed end of said housing andpiston plate seal means provided in the periphery of said piston platefor sealing said piston plate in slidable relationship in said housing;a piston access opening provided in said closed end of said housing andpiston seal means provided in said piston access opening; a pistonextending from said piston plate through said piston access opening andsaid seal means, wherein said piston is sealed in slidable relationshipin said piston access opening by said piston seal means; retainer meansdisposed on the end of said piston extending through said piston accessopening for retaining a portion of the extending end of said pistonoutside of said housing when the quantity of lubricant is reduced insaid housing; a lubricant fitting seated in said housing for selectivelyintroducing fresh lubricant into said housing; and a coil spring locatedin said housing between said piston plate and said closed end of saidhousing for biasing said piston plate toward said open end of saidhousing, whereby said piston plate exerts pressure on the lubricantprovided in said housing and causes the lubricant to coat the wheelbearings, responsive to the bias of said coil spring.
 40. The bearinglubricating device of claim 39 further comprising an air escape ductprovided in said housing for allowing air to escape from said housingwhen the lubricant is introduced into said housing through saidlubricant fitting.
 41. The bearing lubricating device of claim 39further comprising a lubricant weep duct provided in said housing forindicating when said housing is substantially filled with the lubricant.42. The bearing lubricating device of claim 39 further comprising:(a) anair escape duct provided in said housing for allowing air to escape fromsaid housing when the lubricant is introduced into said housing throughsaid lubricant fitting; and (b) a lubricant weep duct provided in saidhousing for indicating when said housing is substantially filled withthe lubricant.
 43. The bearing lubricating device of claim 39 furthercomprising a lubricant supply passage provided in said piston and saidpiston plate, said lubricant supply passage communicating with thelubricant in said housing, and wherein said lubricant fitting isrelocated in said extending end of said piston, said lubricant fittingprovided in communication with said lubricant supply passage, forselectively introducing lubricant into said housing.
 44. The bearinglubricating device of claim 39 wherein said retainer means furthercomprises a flange and a plurality of flange tabs provided in saidflange for engaging said piston, said flange adapted to engage saidclosed end of said housing and arrest the travel of said piston plateinwardly of said housing, responsive to the bias in said coil spring.45. The bearing lubricating device of claim 44 further comprising:(a) anair escape duct provided in said housing for allowing air to escape fromsaid housing when the lubricant is introduced into said housing throughsaid lubricant fitting; and (b) a lubricant weep duct provided in saidhousing for indicating when said housing is substantially filled withthe lubricant.
 46. The bearing lubricating device of claim 44 furthercomprising a lubricant supply passage provided in said piston and saidpiston plate, said lubricant supply passage communicating with thelubricant in said housing, and wherein said lubricant fitting isrelocated in said extending end of said piston, said lubricant fittingprovided in communication with said lubricant supply passage, forselectively introducing lubricant into said housing.
 47. The bearinglubricating device of claim 39 further comprising first color indiciaprovided on said flange and said extending end of said piston and secondcolor indicia provided on said extending end of said piston adjacent tosaid first color indicia, for approximately indicating the quantity oflubricant in said housing, responsive to slidable movement of saidpiston and said piston plate in said housing.
 48. The bearinglubricating device of claim 44 further comprising:(a) an air escape ductprovided in said housing for allowing air to escape from said housingwhen the lubricant is introduced into said housing through saidlubricant fitting; and (b) a lubricant weep duct provided in saidhousing for indicating when said housing is substantially filled withthe lubricant.
 49. The bearing lubricating device of claim 48 furthercomprising a lubricant supply passage provided in said piston and saidpiston plate, said lubricant supply passage communicating with thelubricant in said housing, and wherein said lubricant fitting isrelocated in said extending end of said piston, said lubricant fittingprovided in communication with said lubricant supply passage, forselectively introducing lubricant into said housing. .Iadd.50. A bearinglubricating device for lubricating a bearing, said bearing lubricatingdevice comprising:a housing having a first end and a second end, saidhousing having a housing chamber therein, said housing chamber having afirst end and a second end; a piston slidably disposed in said housingchamber, said housing chamber being divided by said piston into a firstchamber and a second chamber, said first chamber being adapted tocontain a lubricant, said housing providing for communication betweensaid first chamber and the bearing, said piston having one end portionslidably projecting through said second end of said housing chamber andsaid second end of said housing to an outer end of said one end portion;a bias element provided in said housing, said bias element engaging saidpiston for biasing said piston towards said first end of said housingchamber and thereby forcing lubricant from said first chamber towardsthe bearing; and a lubricant fitting for selectively introducing freshlubricant into said first chamber; wherein said one end portion iscolored to provide an external visual indication of whether the quantityof lubricant in said first chamber is sufficient to lubricate thebearing. .Iaddend. .Iadd.51. A bearing lubricating device in accordancewith claim 50 wherein said one end portion of said piston contains alubricant supply passage in communication with said first chamber, andwherein said lubricant fitting is positioned on said outer end of saidone end portion exteriorly of said housing and in communication withsaid lubricant supply passage. .Iaddend. .Iadd.52. A bearing lubricatingdevice in accordance with claim 50 wherein said one end portion has atleast first and second color areas of differing colors, said secondcolor area being located between said first color area and the outer endof said one end portion of the piston. .Iaddend. .Iadd.53. A bearinglubricating device in accordance with claim 50 further comprising an airescape duct provided in said housing for allowing air to escape fromsaid second chamber when lubricant is introduced into said first chamberthrough said lubricant fitting. .Iaddend. .Iadd.54. A bearinglubricating device in accordance with claim 50 wherein said pistoncomprises a piston plate slidably disposed in said housing chamber todivide said housing chamber into said first chamber and said secondchamber, wherein said one end portion is an elongated portion having asmaller diameter than said piston plate and connected to and extendingfrom said piston plate to said outer end. .Iaddend. .Iadd.55. A bearinglubricating device in accordance with claim 54 wherein said pistonfurther comprises a piston seal provided in the periphery of said pistonplate for sealing said piston plate in slidable relationship in saidhousing chamber. .Iaddend. .Iadd.56. A bearing lubricating device inaccordance with claim 50 wherein said second end of said housing has apiston access opening provided therein through which said one endportion extends so as to at least substantially close said second end ofsaid housing. .Iaddend. .Iadd.57. A bearing lubricating device inaccordance with claim 56 wherein said second end of said housing furthercomprises a piston seal provided in the periphery of said piston accessopening for sealing said one end portion in slidable relationship insaid second end of said housing. .Iaddend. .Iadd.58. A bearinglubricating device in accordance with claim 50 wherein said first end ofsaid housing is open to provide communication of said first chamber withsaid bearing. .Iaddend. .Iadd.59. A bearing lubricating device inaccordance with claim 50 wherein said one end portion of said pistoncomprises a retainer positioned externally of said housing to preventsaid one end portion from completely recessing in said second end ofsaid housing responsive to the bias of said bias element when thequantity of lubricant in said first chamber has reached a sufficientlylow level to require recharging of lubricant into said first chamber..Iaddend. .Iadd.60. A bearing lubricating device in accordance withclaim 50 wherein a first color area is positioned on said one endportion such that at least a portion of said first color area extendsoutside said housing when said first chamber contains sufficientlubricant and said first color area is retracted inside the housing whenadditional lubricant should be charged into said first chamber..Iaddend. .Iadd.61. A bearing lubricating device in accordance withclaim 60 wherein said one end portion of said piston contains alongitudinally extending lubricant supply passage in communication withsaid first chamber, and wherein said lubricant fitting is positioned onsaid outer end of said one end portion exteriorly of said housing and incommunication with said lubricant supply passage. .Iaddend. .Iadd.62. Abearing lubricating device in accordance with claim 61 wherein said oneend portion of said piston comprises a retainer positioned externally ofsaid housing to limit the travel of said one end portion inwardly ofsaid housing responsive to the bias of said bias element and to indicatewhen the quantity of lubricant in said first chamber has reached asufficiently low level to require recharging of lubricant into saidfirst chamber. .Iaddend. .Iadd.63. A bearing lubricating device inaccordance with claim 61 wherein said piston comprises a piston plateslidably disposed in said housing chamber to divide said housing chamberinto said first chamber and said second chamber, wherein said one endportion is an elongated portion having a smaller diameter than saidpiston plate and connected to and extending from said piston plate tosaid outer end. .Iaddend. .Iadd.64. A bearing lubricating device inaccordance with claim 63 wherein said piston further comprises a pistonseal provided in the periphery of said piston plate for sealing saidpiston plate in slidable relationship in said housing chamber. .Iaddend..Iadd.65. A bearing lubricating device in accordance with claim 64wherein said second end of said housing has a piston access openingprovided therein through which said one end portion extends so as to atleast substantially close said second end of said housing. .Iaddend..Iadd.66. A bearing lubricating device in accordance with claim 65wherein said second end of said housing further comprises a piston sealprovided in the periphery of said piston access opening for sealing saidone end portion in slidable relationship in said second end of saidhousing. .Iaddend. .Iadd.67. A bearing lubricating device in accordancewith claim 66 further comprising an air escape duct provided in saidhousing for allowing air to escape from said second chamber whenlubricant is introduced into said first chamber through said lubricantfitting. .Iaddend. .Iadd.68. A bearing lubricating device in accordancewith claim 67 wherein said first end of said housing is open to providecommunication of said first chamber with said bearing. .Iaddend..Iadd.69. A bearing lubricating device for lubricating a wheel bearinglocated in a wheel bearing housing, said bearing lubricating devicecomprising:a device housing having a first end and a second end, saidfirst end of said device housing being adapted to be removably securedto the wheel bearing housing, said device housing having a housingchamber therein, said housing chamber having a first end and a secondend; a piston slidably disposed in said housing chamber, said housingchamber being divided by said piston into a first chamber and a secondchamber, said first chamber being adapted to contain a lubricant, saiddevice housing providing for communication between said first chamberand the bearing through said first end of said device housing, saidpiston having one end portion slidably projecting through said secondend of said housing chamber and extending outwardly through said secondend of said device housing to an outer end of said one end portion; abias element provided in said device housing, said bias element engagingsaid piston for biasing said piston towards said first end of saidhousing chamber and thereby forcing lubricant from said first chambertowards the bearing; and a lubricant fitting for selectively introducingfresh lubricant into said first chamber; wherein said one end portion iscolor-coded to provide an external visual indication of the quantity oflubricant in said first chamber. .Iaddend. .Iadd.70. A bearinglubricating device in accordance with claim 69 wherein said one endportion of said piston contains a lubricant supply passage incommunication with said first chamber, and wherein said lubricantfitting is positioned on said outer end of said one end portionexteriorly of said device housing and in communication with saidlubricant supply passage. .Iaddend. .Iadd.71. A bearing lubricatingdevice in accordance with claim 69 wherein said one end portion has atleast first and second color areas of differing colors, said secondcolor area being located between said first color area and the outer endof said one end portion of the piston. .Iaddend. .Iadd.72. A bearinglubricating device in accordance with claim 69 further comprising an airescape duct provided in said device housing for allowing air to escapefrom said second chamber when the lubricant is introduced into saidfirst chamber through said lubricant fitting. .Iaddend. .Iadd.73. Abearing lubricating device in accordance with claim 69 wherein saidpiston comprises a piston plate slidably disposed in said housingchamber to divide said housing chamber into said first chamber and saidsecond chamber, wherein said one end portion is an elongated portionhaving a smaller diameter than said piston plate and connected to andextending from said piston plate to said outer end. .Iaddend. .Iadd.74.A bearing lubricating device in accordance with claim 73 wherein saidpiston further comprises a piston seal provided in the periphery of saidpiston plate for sealing said piston plate in slidable relationship insaid housing chamber. .Iadd.75. A bearing lubricating device inaccordance with claim 69 wherein said second end of said device housinghas a piston access opening provided therein through which said one endportion extends so as to at least substantially close said second end ofsaid device housing. .Iaddend. .Iadd.76. A bearing lubricating device inaccordance with claim 75 wherein said second end of said device housingfurther comprises a piston seal provided in the periphery of said pistonaccess opening for sealing said one end portion in slidable relationshipin said second end of said device housing. .Iaddend. .Iadd.77. A bearinglubricating device in accordance with claim 69 wherein said first end ofsaid device housing is open to provide communication of said firstchamber with said bearing. .Iaddend. .Iadd.78. A bearing lubricatingdevice in accordance with claim 69 wherein said one end portion of saidpiston comprises a retainer positioned externally of said device housingto prevent said one end portion from completely recessing in said secondend of said device housing responsive to the bias of said bias elementwhen the quantity of lubricant in said first chamber has reached asufficiently low level to require recharging of lubricant into saidfirst chamber. .Iaddend. .Iadd.79. A bearing lubricating device inaccordance with claim 71 wherein said first color area is positioned onsaid one end portion such that at least a portion of said first colorarea extends outside said device housing when said first chambercontains sufficient lubricant and said first color area is retractedinside the device housing when additional lubricant should be chargedinto said first chamber. .Iaddend. .Iadd.80. A bearing lubricatingdevice in accordance with claim 79 wherein said one end portion of saidpiston contains a longitudinally extending lubricant supply passage incommunication with said first chamber, and wherein said lubricantfitting is positioned on said outer end of said one end portionexteriorly of said device housing and in communication with saidlubricant supply passage. .Iaddend. .Iadd.81. A bearing lubricatingdevice in accordance with claim 79 wherein said one end portion of saidpiston comprises a retainer positioned externally of said device housingto limit the travel of said one end portion inwardly of said devicehousing responsive to the bias of said bias element and to indicate whenthe quantity of lubricant in said first chamber has reached asufficiently low level to require recharging of lubricant into saidfirst chamber. .Iaddend. .Iadd.82. A bearing lubricating device inaccordance with claim 79 wherein said piston comprises a piston plateslidably disposed in said housing chamber to divide said housing chamberinto said first chamber and said second chamber, wherein said one endportion is an elongated portion having a smaller diameter than saidpiston plate and connected to and extending from said piston plate tosaid outer end. .Iaddend. .Iadd.83. A bearing lubricating device inaccordance with claim 82 wherein said piston further comprises a pistonseal provided in the periphery of said piston plate for sealing saidpiston plate in slidable relationship in said housing chamber. .Iaddend..Iadd.84. A bearing lubricating device in accordance with claim 79wherein said second end of said device housing has a piston accessopening provided therein through which said one end portion extends soas to at least substantially close said second end of said devicehousing. .Iaddend. .Iadd.85. A bearing lubricating device in accordancewith claim 84 wherein said second end of said device housing furthercomprises a piston seal provided in the periphery of said piston accessopening for sealing said one end portion in slidable relationship insaid second end of said device housing. .Iaddend. .Iadd.86. A bearinglubricating device in accordance with claim 79 further comprising an airescape duct provided in said device housing for allowing air to escapefrom said second chamber when lubricant is introduced into said firstchamber through said lubricant fitting. .Iaddend. .Iadd.87. A bearinglubricating device in accordance with claim 79 wherein said first end ofsaid device housing is open to provide communication of said firstchamber with said bearing. .Iaddend.